Abstract: An I.V. flush syringe assembly includes a barrel having an inside surface defining a chamber for retaining fluid, an open proximal end and a distal end including a distal wall with an elongate tip extending distally therefrom having a passageway therethrough in fluid communication with the chamber. A plunger having an elongate body portion and a stopper slidably positioned in fluid-tight engagement with the inside surface of the barrel is provided. Anti-reflux structure for controlling stopper deflection when fluid has been delivered from the chamber and the stopper is in contact with the distal wall is provided.

Abstract: An I.V. flush syringe assembly includes a barrel having an inside surface defining a chamber for retaining fluid, an open proximal end and a distal end with a passageway therethrough in fluid communication with the chamber. An elongate plunger having a proximal end, a distal end and a stopper is slidably positioned in fluid-tight engagement with the inside surface of the barrel for drawing fluid into and out of the chamber by movement of the stopper relative to the barrel. The plunger includes anti-reflux structure for minimizing stopper deflection when fluid has been delivered from the chamber and the stopper is being forced against the distal end of the chamber.

Abstract: An I.V. flush syringe assembly includes a barrel having an inside surface defining a chamber for retaining fluid, an open proximal end and a distal end including a distal wall with an elongate tip extending distally therefrom having a passageway therethrough in fluid communication with the chamber. A plunger having an elongate body portion and a stopper slidably positioned in fluid-tight engagement with the inside surface of the barrel is provided. Anti-reflux structure for controlling stopper deflection when fluid has been delivered from the chamber and the stopper is in contact with the distal wall is provided.

Abstract: A method of making a flush syringe assembly comprises providing a plurality of syringe barrels having a chamber with a conically-shaped distal wall and providing a plurality of stoppers having a conically-shaped distal surface. The method further includes selecting a stopper from the plurality of stoppers and a barrel from the plurality of barrels so that the total included angle of the distal wall of the selected barrel is greater than the total included angle of the selected stopper distal surface, and inserting the selected stopper into the chamber of the selected barrel.